Telegraph transmitter



kwa N 1^ Nov. 15, 1960 F. c. MoEBlUs 2,960,572

TELEGRAPH TRANSMITTER Filed June 23, 1958 4 Sheets Sh t FIG. l

if, ,933933339339 1////////// f 4;@33339335! ,9933333935332 ATTORNFY Nov. 15, 1960 F. C. MOEBIUS TELEGRAPH TRANSMITTER 4 Sheets-Sheet 2 Filed June 23. 1958 WHHHHHWW INVENToR FREDERICK C. MOEBIUS Q ATTQR EY Nov. 15, 1960 F. c. MoEBlUs 2,960,572

TELEGRAPH TRANSMITTER Filed June 23, 1958 v 4 Sheets-Sheet 3 o HHM.

INVENTOR FREDERICK C. MOEBIUS ATTORNEY Nov. 15, 1960 F. C. MQEBIUS 2,960,572

TELEGRAPH TRANSMITTER Filed June 23, 1958 4 Sheets-Sheet 4 FIG. 7

FIG. 8

FIG. 9

FIG. IO

INVENTOR FREDERICK C. MOEBIUS TELEGRAPH TRANSMITTER Frederick C. Moebius, Barrington, Ill., assignor to Teletype Corporation, Chicago, lil., a corporation of Delaware Filed June 23, 1958, Ser. No. 743,820

10 Claims. (Cl. 178-81) The present invention pertains to telegraph transmitters and more particularly to transmitters of the cam type.

An important object of the present invention is to provide a signal generator having a simple and efficient organization of elements conducive to smooth and rapid operation of the transmitting contact mechanism.

Another object of the invention is to provide in a telegraph transmitter a signal generator having a minimum of operating elements to thereby enhance the signal transmitting facility thereof.

Specifically, the transmitter according to the present invention embraces a signal generator comprising a cam drum having a series of cam projections arranged helically to effect through a corresponding series of key lever controlled bell crank levers and an associated rockable bail member, the conditioning of a transfer member, and a transferring device including a llutter cam for actuating the transmitter contact through a second rockable member according to the operating condition of said rockable bail member. The invention also features a novel non-repeat device.

The foregoing and other objects of the invention will be more apparent in the following detailed description of the invention when taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a perspective view of the combined transmitting and receiving apparatus embodying the present invention;

Fig. 2 is a cross-sectional view of the keyboard;

Fig. 3 is a front elevational View, partly in section, of the signal generator according to the invention;

Fig. 4 is an elevational view of the contact assembly;

Fig. 5 is a fragmental plan view of the keyboard apparatus showing the signal generator according to the invention;

Fig. 6 is a front elevational view, partly in section, showing the non-repeat feature of the present invention; and

Figs. 7, 8, 9 and 10 are views illustrating various operating positions of the non-repeat mechanism.

Having reference to Fig. 1 of the drawings, the numeral 11 designates the telegraph apparatus generally, comprising a keyboard transmitting portion 12 and a printer portion 13. The printer portion 13 is the subject of co-pending application Serial No. 734,907, led May 13, 1958, by R. W. Nordin, and comprises a type wheel 14 mounted on a carriage movable with respect to a platen 15. The keyboard apparatus 12 comprises primarily a base 16 adapted to support a code bar selector mechanism 17 of the type shown in U.S. Patent No. 1,884,753, issued to H. L. Krum. Selector mechanism 17 comprises a plurality of pairs of code bars 18 and 19.

A plurality of key members 21 provided with portions 22, as may be seen in Figs. 2 and 5, are adapted to span said code bars 18-19 and are held in their up- Ward position against an 11p-stop rod 23 by individual Patented Nov. 15, '1960 springs 24. Key members 21 are provided with key tops 25 adapted to extend through the housing 26 to provide a key arrangement well known in the art (Fig. 1). Each key member 21 is arranged to depress one of the code bars 18 or 19 of each pair of bars, and through the medium of rocker arms 27, the bar 18 or'19 lifts the companion bar of its pair to reciprocate longitudinally a permutation bar 28 cooperatively associated with and subjacently disposed to each pair of bars 18 and 19 to impart corresponding movement to punch interponents (not shown) such as disclosed in U.S. Patent No. 2,059,- 250. The bars 28 are thus adapted to be set in characteristic combinations, and for this purpose, bars 18 and j 19 are provided with notched upper edges, the bars of each pair being complements; that is, the high portions of one bar are disposed opposite to the low portions of the other bar of the same general pair.

One of each pair of code bars 18-19 (in the present embodiment, code bar 18) is provided with an endwise extension 29 (Figs. 3, 5 and 6) terminating in a bifurcation or open-ended slot, the upper prong of which cooperates with an associated bell crank of a plurality of bell cranks 31, as will presently appear, and the lower prong of which cooperates with a clutch release bail 32, as will hereinafter be described. The bell crank levers 31 are mounted pivotally on a pivot shaft 33, and are each provided with depending arms 34 and horizontal arms 35.

The depending arms 34 of levers 31, as shown in Fig. 3, are guided in slots provided therefor in a guide member 36, suitably positioned in the apparatus. Bell crank levers 31 are normally urged clockwise by individual springs 37 having one end anchored in said guide 36 and the other end connected to a spring hook 38 in arm 35. Each arm 35 is provided with a cam follower projection 39 adapted to cooperate with an individual cam 41 carried on shaft 42. The apices of cams 41 are arranged helically, in the well known manner, to effect sequential operation of the bell cranks 31.

Arms 35 of bell cranks 31. are provided at their extremities with downwardly directed projections 43 adapted to cooperate with a vertically directed bail blade 44 of a bail member 45 mounted pivotally on a shaft 46. Bail member 45 is normally biased clockwise by a spring 47. The front end of blade 44 is adapted to extend through an opening 48 in a transfer member 49 carried pivotally at the upper end of a flutter lever 51 pivotally mounted on a stud 52 secured to the frame portion 53 of the transmitter 12. Flutter lever 51 is provided with a cam follower portion 54 adapted to .ride on the periphery of a flutter cam 55 due to the normal counterclockwise bias imparted thereto by a spring 56.

Flutter cam 55 is carried on shaft 42 and is adapted to rotate with the cams 41. Flutter cam 55, in the present embodiment, is provided with seven humps or apices, one for each element of a five-unit code, one for the start interval and one for the stop interval. Transfer member 49 is provided with a pair of abutments 57 and 58 adapted under predetermined operating conditions to cooperate with a pair of abutments 59 and 61 of a rocker member 62 mounted pivotally on shaft 46. As the member 62 is rocked to its counterclockwise position (as shown) or to its clockwise position, as will hereinafter appear, it is retained in either of said positions by a detent lever 63 having a stabber portion 64 adapted to co-act with notches 65 in said rocker member 62. Detent lever 63 is mounted on pivot stud 66 and is normally urged counterclockwise by a spring 67.

Connected pivotally at 68 to the rocker member 62 is a link 69 adapted to cooperate with elements of a transmitting contact assembly located in a suitable housing 71 mounted in the signal generator portion of the transmitter 12' (Figs. 1, 3, 4 and 5). The other end of link 69 is connected to the stem 72 of a T-shaped contact lever 73 mounted pivotally at 74 on a fulcrum -member 75 which cooperates Vwith a V-shaped notch 76 in a bracket 77 mounted-inthehousing 71. A spring 78 having one endfattached to the member 75 has the other end attached to a spring anchor bar 79. The spring 78 is thus so connected that the number 75 will be urged normally ina clockwise direction (Fig. 4) about pivotal connection 76-77, urging the contact points 81 toward their associated-contact points 82. With the pivotal connection 74 centrally located, a balanced pressure is exerted with respect to both of thecontact points 81.

In actual practice the operating lever 73 will normally be held-in such a position that only one contact pair 81-82fwill be closed at a time. Since the rockable member 62 will be in one of its two positions, or moving from one-to the other, the T-lever 73 will be positioned in such a manner as to cause one of the contact points 81 to pivot about its associated contact point 82. As a change of selection is made in the operating link 69, under the control of the utter lever arrangement, as will hereinafter appear, the T-lever 73 will be moved from one position to the other, and as the lever 73 is not pivoted about an external point, it will pivot about the contact pair which is desired to lbe closed. In this manner, bounce and vibration will be eliminated.

Associated with the selector code bars 18--19 is a universal bar 83, so-called because it is operated upon every depression of a key 25. As viewed in Fig. 6, the universal bar 83 is provided with a downwardly and rightwardly directed extension 84 which carries pivotally at its extremity a clutch trip pawl 85, which is normally biased clockwise by a spring 86, to hold its laterally directed extremity 87 against the rearward arm (Fig. 6) of the clutch release bail 32. The bail 32 is U-shaped to provide a double bearing therefor on shaft 33, the web portion S8 of said bail adapted to cooperate with lever arms 89 and 91, as will presently appear. Arms 89 and 91 are lmounted pivotally on a pivot shaft 92 supported in plates 53 and 93, and are normally urgedv in a clockwise direction by individual springs 94. As will hereinafter appear, `arm 89 is a latching arm, and arm 91 is an interfering arm.

Bail 32 is also provided, in the plane of its rearward vertical arm, with a cam follower arm 95 (Figs. 5 and 6) adapted `to cooperate with a reset cam 96 carried on shaft 42. A spring 97 normally urges, through arm 95, the bail 32 clockwise. Cams 41, 55 and 96 are mounted on a sleeve 98 (Fig. 5) which in turn is carried on the shaft 42. Also mounted on the sleeve 98 is a clutch member 99 which is provided with a projection 101 on which is pivotally mounted a clutch pawl 102 which is adapted, under certain conditions, to engage a constantly rotating toothed member 103. Member 103 and a gear 104 integral therewith are freely carried on shaft 42, and gear 104'meshes with a gear -105 xed to motor shaft 106 ,of a motor-(not shown). Pawl 102 is normally biased clockwise by a `coiled spring 107.

Pawl 102 is held out of'engagement with the toothed portion 103 by projection 108 of a stop lever 109 freely mounted pivotally on the shaft 33. Lever 109 is also provided with a laterally directed projection 111 adapted to cooperate with the aforementioned rearward arm of the clutch release bail 32. Lever 109 is normally biased counterclockwise by aV spring 112distended between an arm 113 of lever 109 and a spring post 114.secured to plate-93, so that the lateral projection 111 normally bears against said rearward arm of bail 32. Clockwise rotation of arm109, as will hereinafter appear, is limited by. a stop 115'cut in the plate 93.

A repeat key lever 1.16 (Fig. 6) is provided which has axed thereto a member 117 having a downwardly and rightwardly directed arm terminating in .a reverted end 118:5.adapted`to cooperatewith a laterally directed projection 119 on a latch member 121 mounted pivotally on a pin 122. Latch member 121 is normally biased clockwise -by a spring 123 stretched between latch 121 and a spring post 124 secured to plate 93, to hold the projection 119 against :the reverted end 118. The spring 123 is weaker than the key lever spring 24 of key lever 116, so that the spring 24 predominates in holding the key lever 116 in its upward or unoperated position.

In the operation of the apparatus according to the present invention, a key 25 is depressed to set the code bars 18-19 permutatively, in the well known manner, and substantially simultaneously, to initiate, through the universal bar 83, the rotation of the selector cam sleeve 98. More specifically, as the code bars 18-19 are set, the upper prongs 125 (Fig. 3) thereof will either block or unblock the depending arms 312- to prevent or permit, respectively, the bell crank levers 31 to follow the periphery of their respective selector cams 41, to correspondingly actuate or not actuate the bail member 4S toy position the transfer lever 49 to bring either the abutments 57-59 into register, or the abutments 58-61 into register. The followers 39 of levers 31 if permitted (by the unblocking of arm 34 by prong 125) will fall -into the depression in cam 41 just prior to the time a hump on the flutter cam 55 urges the transfer lever 49 righ-twardly to rock the member 62 in a direction depending upon the relative positions between abutments 57--59 and v58-61. In other words, in timed relation to the actuation of bell crank levers 31 by cams 41, the flutter cam 55 vibrates the lever 51 to actuate the transfer lever 49 in accordance with the position of bail blade 44 to, in turn, actuate or rock the member 62, which, through link 69, rocks the contact lever 72 to actuate contacts 31-82.

To .initiate the rotation of the cam sleeve 98 to effectuate lthe operation of the transmitting contacts 81-82 in accordance with the setting of code bars 18-19 in response to the actuation of keys 25, the pawl carried on the universal bar extension 84 acts, upon the downward movement of the universal bar 83, to ftrip the lever arm 89 from engagement with the web portion 88 of the clutch release bail 32, whereupon bail 32 is rotated clockwise by its spring 97. As bail 32 is thus rotated, its rearwardly disposed depending arm acts, through laterally directed projection 111 of stop lever 109, to disengage the stop projection '108 thereof from the clutch pawl 102 (Figs. 5 and 6). Spring 107 urges the pawl 102 clockwise into enaggement with the constantly rotating member 103 to effect the rotation of cam sleeve 98. Referring to Fig. 3, it is seen that upon the rotation of sleeve 98, the selector cams 41 and utter cam 55 thereon will effectuate the operation, through lever 31, of the bail 4S in accordance with the setting of the code bars 18-19. Thus, if any of the levers 31 are blocked by prongs of code bar 18, they cannot rotate when the depression in the periphery of the associated cam 41 vis presented to the cam follower 39, and hence bail 45 is not actuated, thereby allowing abutments 57 and 59 to remain in register or coincidence when the flutter cam 55-tbtrough the flutter lever 51 operates the transfer member-49, to thereby rock the member 62, which through link 69-and contact lever 72 operates the contacts 81- 82 tto impress one signalling condition on the signal line. Gn the other hand, lif any of the levers 31 are not blocked, they are permitted to rotate clockwise when their cam follower projections 39 encounter a depression in cams 41 and engage and rotate bail 45 counterclockwise to bring the abutments 58 and 61 into register when the flutter lever 51 is actuated clockwise. The engagementof the abutments 58 and 61 rocks the member 62 counterclockwise (if it has been previously rocked to its clockwise position) to thereby operate the contacts $1- 82k to-impress an opposite signalling condition on the signal line.

The clutch comprising the pawl 102 and-the constantly rotating toothed member 103 is a so-called single revolution clutch; that is, it can make only one revolution upon each depression of a key lever. Thus, as a key lever is depressed, the universal bar 83 is lactuated downwardly to cause its pawl 85, first, to engage the arms 89 and 91, as shown in Fig. 7. Then, upon further downward movement, pawl 85 will urge arms 89 and 91 to the position shown in Fig. 8 to disengage the latch arm 89 from the web 88 of the clutch release bail 32, as previously mentioned. Spring 97 will then urge the bail 32 clockwise to the position shown in Fig. 9 whereat the stop projection 108 has become disengaged from the clutch pawl 102 to permit pawl 102 to engage with the clutch member 103. The clockwise movement of bail 32 is limited by the stop 115. In the entreme clockwise position of bail 32, the web 88 thereof will be positioned in the vertical path of prongs 128 of code bars 18 and 19, and will cooperate with said prongs 128 to lock said code bars 18 and 19 against ver-tical movement until bail 32 has been returned to its counterclockwise position. Now, as the clutch 102-103 rotates the member 99, and hence the cam sleeve 98, the ca m 96 acts upon arm 95 to rotate the bail 32 counterclockwise to the position shown in Fig. l0 whereat the bail 32 is again lartched by the latch arm 89 and the stop projection 108 is again interposed into the path of rotation of clutch pawl 102 so that as the arm 126 of clutch pawl 102 strikes the stop 108, the clockwise movement of the clutch member 99 will cause pawl 102 to be rotated counterclockwise to elect the disengagement of the clutch members 102 and 103, Ithus insuring the rotation of the clutch sleeve 98 for only a single revolution, even though the universal bar 83 and clutch release pawl 85 are held depressed. Thus, a non-repeat means is featured if a key lever is held depressed.

However, the present invention also provides a more positive non-repeat feature by providing the auxiliary or interfering arm 91 for the clutch release pawl 85 which prevents a repeat operation until after the key lever has rst been restored to its normal released or upward position. As sho-wn in Fig. 6, the pawl 85 in its downward movement, first strikes the arm 91, and rotates said arm 911 to the position shown in Fig. 7 wherealt it engages both arms 89 and 91. Then, upon further downward movement to the position shown in Fig. 8, the bail 32 is released for clockwise rotation, as previously described, to the position shown in Fig. 9. However, the pawl 85 is pushed ahead by the bail 32, but nevertheless the pawl 85 is still in engagement with the interfering arm 91. If the pawl 85 is depressed farther than that shown in Fig. 9, its laterally directed extremity 87 will merely engage fthe shoulder 127 of the interfering arm 91. As shown in Fig. l0, the interfering arm 91 is effective to prevent the re-engagement of lateral portion 87 of pawl 85 with the latching arm 89 until after the key lever has been fully released and the universal bail 83 returned to its ultimate upward position or to the position shown in Fig. 6. It is therefore observed that the interfering arm 91 provides a positive protection against an inadvertent repeat operation.

In the event that repeat operation is desired, a repeat key lever 116 is provided, which, as previously described, is provided with an arm 117 adapted to cooperate with a latch member 121, so that when the repeat key lever 116 is depressed, the latch 121 is permitted to be urged downwardly by its spring 123 to cause the hooked eX- tremity of latch 121 to bear against the top of the lateral portion 111. Then, when the bail 32 has been released upon the depression of another key lever (it being understood that the repeat key lever 116 will be heldv depressed simultaneously and as long as a character key 25 is also held depressed), the portion 111 will be moved clockwise with the bail 32, and the hooked end of latch 121 will engage the portion 111 and hold the lever 109, and hence the stop projection 108 away 6 from the pawl 102, which will thus remain in engage-4 ment with the constantly rotating toothed member 103 to effectuate the continuous rotation of cam sleeve 98 to transmit a signal repeatedly over the signal line.

While the invention has been described in detail with respect to a particular application thereof, it will he understood that modications and variations may be made without departing from the spirit and scope of the invention.

What is claimed is:

1. A signal generator, which comprises a plurality of helically arranged cams, a cam follower associated with each cam, permutatively settable means for selectively precluding responsive cooperation of said cam followers with their respective cams in accordance with one of two selective attributes of code signal elements and for selectively permitting such cooperation in accordance with the other of said attributes, means for rotating said cams, an oscillatable member adapted to be engaged by the cooperatively responsive ones of said cam followers and oscillated thereby, a rockable member, a transfer member articulated to said oscillatable member for oscillation therewith, means for engaging said transfer member with said rockable member repetitiously in timed relation to the oscillation of the oscillatable member by said cam followers for presenting said rockable member in either of two positions in accordance with the oscillatory disposition of said oscillatable member, and transmitting contacts controlled by said rockable member for generating code signal elements.

2. A signal generator, which comprises a plurality of helically arranged cams, a cam follower associated with each cam, means for rotating said cams, permutatively settable means for selectively precluding responsive cooperation of said cam followers with their respective cams in accordance with one of two selective attributes of code signal elements and for selectively permitting such cooperation in accordance with the other of said attributes, an oscillatable member engageable by the cooperatively responsive ones of said cam followers and oscillatable thereby, a rockable member, a flutter cam rotatable with said cams, a transfer lever mounted pivotally adjacent said flutter cam and urged into continuous responsive cooperation with said utter cam, a transfer member mounted pivotally on said transfer lever and articulated to said oscillatable member, said flutter cam adapted to operate said transfer lever to cause said transfer member to engage and rock said rockable member in timed relation with the oscillations of said oscillatable member and in accordance with the oscillatory position of said oscillatable member, transmitting contacts, and a linkage interconnecting said rockable member and said transmitting contacts and operative to open and close said transmitting contacts to transmit code signal elements.

3. A transmitter, which comprises a plurality of permutatively settable means including instrumentalities adapted to be set in either of two positions in accordance with either of two signal conditions of code signal elements, a plurality of helically arranged cams, means for rotating said cams, a cam follower associated with and urged into responsive cooperation with each cam, said instrumentalities when in one of said two positions adapted to preclude responsive cooperation of said cam followers with their associated cams and adapted to pervmit such responsive cooperation when in the other of said two positions, an oscillatable member engageable by said cooperatively responsive ones of said cam followers and oscillatable thereby, a rockable member adapted to be rocked from either to the other of two positions, a Hutter cam mounted for rotation with said first-mentioned cams, a transfer lever mounted pivotally adjacent said flutter cam and having continuous responsive engagementwith said Hutter cam, a transfer member mounted pivotally on said transferlever and articulated to said oscillatable member, said transfer member adapted to be moved by said transfer lever into engagement with said rockable memberA in timed relation with the oscillations of said oscillatable member to rock said rockable member in accordance. with the oscillatory position of said oscillatable member, transmitting contacts, and a linkage interconnectiing said rockable member and said contacts and operative to open and close said contacts to transmit code signal elements.

4. A transmitter, which comprises a plurality of individually operable keylevers, a plurality of code bars presentable by said keylevers in either of two positionsl in accordance with one or the other of twoselective conditions of signal elements of a predetermined code, a plurality of helically arranged cams with each cam having one peripheral low portion, means' for rotating said cams, a cam follower lever associated with each cam and urged into responsive cooperation therewith unless precluded from dropping into the peripheral low portion of its associated cam by the associated code bar when presented in one of said two positions, a bail common to the cam follower levers and operable to a predetermined position by each cam follower lever cooperatively responding to the low portion of its cam, a utter cam having lobes equal in number to the number of `signal elements transmissible for each operation of a keylever, a transfer lever biased for continuous engagement with said flutter cam, a transfer member articulated to said bail and pivota-lly connected to said transfer lever, a rockable member mounted adjacent said transfer member and adapted to be engaged and rocked into either of two positions by said transfer member in accordance with the .position of said bail as determined by said cam follower levers when said transfer lever is moved by said flutter cam to engage said transfer member with said rockable member, a pair of transmitting contacts, and a contact lever linked to said rockable member and adapted to open and close said transmitting contacts in accordance with the positions of said rockable member to transmit code signal elements.

5,. A transmitter, which comprises a plurality of permutatively settable means including instrumentalities adapted to be set in either of two positions in accordance with either of two signal conditions of code signal elements, a plurality of helically arranged cams, means for rotating said cams, a cam follower associated with and urged into responsive cooperation with each cam, said instrumentalities when in one of said twopositions adapted to preclude responsive cooperation of said cam followers with their associated cams and adapted to permit such responsive cooperation when in the other of said two positions, an oscillatable member engageable by said cooperatively responsive ones of said cam followers and oscillatable thereby, a rockable member adapted to be rocked from either to the other of two positions, a flutter cam mounted for rotation with said inst-mentioned cams, a transfer lever mounted pivotally adjacent said flutter cam and having continuous responsive engagement ywith said flutter cam, a transfer member mounted pivotally on said transfer lever and articulated to said oscillatable member, said transfer member adapted to be moved by said transfer lever into engagement with said rockable member in timed relation with the oscillationsof said oscillatable member to rock said rockable member in accordance with the oscillatory position of said oscillatable member, transmitting contacts, a linkage interconnecting said rockable member and said contacts and operative to open and close said contacts to transmit code signal elements, and means for limiting said cam rotating means to a single cycle upon each operation ofra key and interfering means for preventing re-operation of said cam rotating means by any key prior to the release of said operated key.

.6. A transmitter, which` comprises a plurality of permutatively settable means controlled by said keys including instrumentalities adapted to be set in either of two positionsin accordance with either of two signal condi- 'tions of code signal elements, a plurality of helically arranged cams, means for rotating said cams, a cam foltion with each cam, said instrumentalities when in one of said two positions adapted to preclude responsive cooperation of said cam followers with their associated cams and adapted to permit such responsive cooperation when inthe other of said two positions, an oscillatable member engageable by said cooperatively responsive ones of said cam followers and oscillatable thereby, a rockable member adapted to be rocked from either to the other of two positions, a utter cam mounted for rotation with said rst-mentioned cams, a transfer lever mounted piv otally adjacent said utter cam and Ihaving continuous responsive engagement with said flutter cam, a transfer member mounted pivotally on said transfer lever and articulated to said oscillatable member, said transfer member adapted to be moved by said transfer lever into engagement with said rockable member in timed relation with the oscillations of said oscillatable member to rock said rockable member in accordance with the oscillatory position of said oscillatable member, transmitting contacts, a linkage interconnecting said rockable member and said contacts and operative to open and close said contacts to transmit code signal elements, latching means for limiting said cam rotating means to a single cycle, tripoff means controlled by the operation of a key for releasing Isaid -latching means, and interfering means for preventing re-operation of said tripoff means until release of said operated key.

7. A transmitter which comprises a plurality of individually operable keylevers, a plurality of code bars presentable by said keylevers in either of two positions in accordance with one or the other of two selective conditions of signal elements of a predetermined code, a plurality of helically arranged cams with each cam having one peripheral low portion, a source of rotative power, a single revolution clutch which includes latching means for connecting said source of rotative power to said cams when released and for disconnecting said rotative power when re-operated, trip-off means actuated by the keylevers for releasing said latching means, means for reoperating said latching means near the end of one revolution of said cams, interfering means for preventing said trip-oit means from again releasing said latching means until release of an operated keylever, a bell crank lever associated withpeach cam and urged into responsive cooperation therewith and effectively cooperable unless precluded by their individual code bars from dropping into the peripheral low portions of their associated cams when said code bars are presented in one of two positions, a bail common to the bell cranks .and operable to a predetermined position by each bell crank cooperatively re- -sponding to the low portion of its cam, a flutter cam having lobes equal in number to the number of signal elements transmissible for each operation of a keylever and mounted for rotation with said cams, a transfer lever l biased for continuous engagement with said flutter cam,

a transfer member articulated to said bail and pivotally connected to said transfer lever, a rockable member mounted adjacent said transfer member and adapted to be engaged and rocked into either of two positions by said transfer member in accordance with the position of said bail as determined by said bell crank lever when said transfer lever is moved by said flutter cam to engage said transfer member with said rockable member, a pair of transmitting contacts, and a contact lever linked to said rockablemember and adapted selectively to open and close said transmitting contacts in accordance with the positions of said rockable member to transmit code signal elements.

Y 8. In combination, a series of keys, a plurality of means controlled by said keys, single-cycle means for operating'said key controlled means, means for latching said singlefcycle operating means in an unreleased condition, trip-oit means operated upon the actuation of any one key of said keys to unlatch said latching means to release said single cycle operating means, and interfering means for preventing the re-operation of said trip-olf means by any of said keys until the restoration of said one actuated key.

9. In combination, a series of keys, a plurality of means controlled by said keys, cyclically operable means effective upon the actuation of any of said keys to operate said key controlled means, means for limiting said cyclically operable means to a single cycle upon the continued actuation of any one of said keys, and means for precluding initiation af a second cycle of operation of said cyclically operable means by any key until the next previously actuated key has been deactuated, said precluding means comprising means for latching said cyclically operable means in a dormant condition, trip-off means operated upon the actuation of any `key to unlatch said latching means, and interfering means for preventing re-Operation of said trip-o means by any key until the next previously actuated key has been deactuated.

10. In combination, a series of keys having normal positions and adapted to be manually depressed into operated positions, means to return said keys to their normal positions upon being depressed, a plurality of means controlled by said keys, cyclically operable means for operating said key controlled means, latching means for normally maintaining said cyclically operable means in a restrained condition and effective upon being unlatched to release said cyclically operable means, trip-olf means operable upon the depression of any one of said keys to unlatch said latching means, means for relatching said latching means to limit said cyclically operable means to a single cycle of operation upon the continued depression of said one key, and interfering means interposed in the path of said trip-olf means to prevent said trip-off means from again unlatching said latching means upon the depression of any other key until said one depressed key has been returned to its normal position.

References Cited in the le of this patent UNITED STATES PATENTS 2,158,066 Evans May 16, 1939 2,848,089 Smathers Aug. 19, 1958 

